A number of different types of current sources have been developed to deliver electric currents. Such current sources include, for example, independent current sources that are configured to deliver a constant current and dependent current sources that are configured to deliver a current that is proportional to some other voltage or current in a circuit. Current sources that deliver an amount of current that is controllable at a relatively high degree of resolution are desirable.
The description above is presented as a general overview of related art in this field and should not be construed as an admission that any of the information it contains constitutes prior art against the present patent application.